Effects of 6 times daily milking during early versus full lactation of Holstein cows on milk production and blood metabolites

Abstract

An experiment was conducted to determine the effects of different milking frequencies on entire lactation production performance in Holstein cows. One hundred twenty Holstein cows were assigned to 3 milking treatments (35 multiparous and 5 primiparous cows in each): 1) milking 6 times daily for the entire lactation (6x); 2) milking 6 times daily for the first 90 d in milk (DIM) and switching to 3 times daily milking afterward (6x-3x); and 3) milking 3 times daily for the entire lactation (3x). Milk yield was recorded every other day during the first 60 DIM and on 2 consecutive days per week subsequently. Cows were weighed and scored for their body condition immediately after parturition and monthly afterward. Blood and milk samples were taken from each cow on 30, 60, 90, 120, 150, 210, and 270 DIM, with an additional blood sampling on 15 DIM. Milk and fat corrected milk yield was greater for 6x and 6x-3x cows than for 3x cows (36.82, 37.32, and 36.1, 36.75 versus 34.56, 35.33 kg/d, respectively) during the experimental period. Milk fat and lactose percentage were not different among treatments, but milk protein was lower in 6x cows than in 6x-3x and 3x cows. Blood glucose concentration was higher and blood nonesterified fatty acids and beta-hydroxybutyrate concentration were lower in 3x cows than in 6x and 6x-3x cows during early lactation. Dry matter intake was greater in 6x cows than in 6x-3x and 3x cows (23.05, 22.58, and 22.45 kg/d, respectively). The 3x cows began to gain weight earlier than the 6x and 6x-3x cows, but there was no difference among groups for BW change regarding the entire experimental period. These results indicate that increasing milking frequency to 6 times daily increases milk yield only during early lactation and that there are no advantages of milking 6 times daily compared with 3 times daily during the mid and late lactation periods. Given the results of this study and the economical aspects of production, milking 6 times daily until 90 DIM and subsequently switching to milking 3 times daily is preferred.

Short- and long-term effects of high milking frequency during the first 21 days of lactation on production and reproductive performance in high-lactating cows

“…older cows) are less responsive to frequent milking. A similar assumption was made by Eslamizad et al (2010).…”

“…These results might prove the hypothesis that a narrow window exists after calving when the mammary gland is responsive to frequent milking (Wall and McFadden, 2008). The duration of 21 days after calving seems to be sufficient because a longer duration of HMF, 42 or 90 days (Bar-Peled et al, 1995;Eslamizad et al, 2010), did not have any additional effect on milk yield. A few other studies demonstrated that an even shorter HMF period (1 to 14 or 7 to 21 days) might have a persistent effect similar to that found in this study with a 21-day period (Hale et al, 2003;Dahl et al, 2004;Wall and McFadden, 2007).…”

“…Several hormones have been reported to regulate galactopoietic effects of frequent milking on milk production in cows, one of them being prolactin (PRL) (Dahl et al, 2004;Wall and McFadden, 2008). Nevertheless, there is no evidence for galactopoietic effects of PRL during an established lactation in ruminants (Plaut et al, 1987;Wall et al, 2006;Eslamizad et al, 2010). The latter authors, who reported that frequent milking does not alter the PRL concentrations at any specific sampling time during HMF, suggested that increasing milk production occurs via local factors rather than stimulation of PRL secretion.…”

“…Shortening the 'window' of frequent milking to 6 weeks (Bar-Peled et al, 1995) or 3 weeks during early lactation resulted in a carryover effect on milk production for the entire lactation (Hale et al, 2003;Dahl et al, 2004;Wall and McFadden, 2007). Similarly, milking six times a day starting 1 or 4 days after calving and continuing for 21 days resulted in higher production performance relative to that achieved by milking six times a day throughout the entire lactation (Eslamizad et al, 2010). Soberon et al (2010) reported that primiparous cows respond better to high milking frequency (HMF), that is, four times a day, than multiparous cows; however, whether the HMF × lactation interaction is also relevant for 6× milking frequency is not clear.…”

“…Nevertheless, in most of the studies examining milking six times a day, the number of cows was relatively small (Bar-Peled et al, 1995;Dahl et al, 2004;Eslamizad et al, 2010). In light of this, we examined the interaction between milking six times a day in early lactation and lactation age.…”